Tobacco use is one of the most potent avoidable causes for cardiovascular (C-V) disease. Epidemiologic studies indicate that even small amounts of secondhand smoke (SHS) exposure increase C-V disease risk. However, the long-term effect of childhood SHS exposure on the life course C-V disease risk is not clear. Importantly, data on dose-response relationship, interaction of SHS with C-V risk factors and racial (black-white) divergence are limited. The proposed research is designed to test the hypothesis that childhood SHS exposure and its impact on C-V disease risk from childhood to adulthood vary by race within a black-white population. In response to the FOA (PA-11-244) Effects of Secondhand Smoke on Cardiovascular and Pulmonary Disease Mechanisms (R01), the proposed research is directed to the following hypothesis-based Specific Aims: 1) to examine the impact of childhood SHS exposure on longitudinal C-V risk variables profile from childhood to adulthood in black versus white nonsmoking cohorts. The C-V risk variables include obesity measures, glucose, insulin, lipids and blood pressure measured serially since childhood, and markers of inflammation, oxidative stress and endothelial function measured in adulthood; 2) to determine the independent effect of childhood SHS and its joint effect with C-V risk variables on adult subclinical C-V structure/function changes in black versus white nonsmokers. The subclinical C- V structure/function measures include carotid artery intima-media thickness, aorta-femoral pulse wave velocity, arterial wall compliance, and left ventricular geometric remodeling and function; 3) to determine the joint effect of childhood SHS and birth weight on longitudinal C-V risk variables profile from childhood and adult subclinical C-V structure/function changes in black versus white nonsmokers. The above specific aims will be examined using a longitudinal cohort followed since childhood in the Bogalusa Heart Study, a long-term biracial (black-white) community-based epidemiologic study of C-V disease beginning in childhood since 1973. The proposed study cohort consists of 800 white and 800 black adults, aged 29-52 years, who already have data on C-V risk factor variables measured serially 6 times from childhood and birth weight in the entire cohort and adulthood subclinical C-V structure/function measures on 50% of the cohort. The findings from the proposed research will provide further insights into the potential underlying mechanisms of C-V disease and help in the implementation strategies of primordial prevention in early life. PUBLIC HEALTH RELEVANCE: Cigarette smoking is one of the avoidable causes for cardiovascular disease. Even small amounts of secondhand smoke exposure increase cardiovascular disease risk. Findings from this study will provide further insights into the potential underlying mechanisms of C-V disease associated with the long-term influence of secondhand smoke exposure in childhood, help strengthen the preventive strategies in early life, and promote comprehensive smoke-free legislation.